Method and apparatus for insertion of joint material in plastic concrete

ABSTRACT

A method and apparatus for inserting joint strip material in a slab of plastic concrete or the like. The apparatus includes an elongated frame for orientation transversely of the slab and transportable in successive movements longitudinally of the slab. The frame mounts a cart adapted to be driven along the frame and carrying a strip guide or tube movable through the plastic concrete to embed the joint strip material. The cart also carries a pan which rides upon the concrete surface behind the strip guide to sense the height of the concrete, initiate operation of a means to adjust the height of the strip guide accordingly, and also smooth the concrete surface. This controls the depth of insertion of the strip material ans smooths the surface of the concrete disrupted by the insertion. The frame includes side forms engageable with the side edges of the concrete slab to preserve their integrity during the insertion operation, the forms being automatically retractable out of such engagement immediately upon longitudinal movement of the main frame. The joint strip material is unwound from a reel upon a strip unreeling traverse of the cart, held in position by clamping arms during an opposite insertion traverse of the cart, and severed upon completion of the insertion traverse. In a second embodiment feed wheels are used instead of the clamping arms.

United States Patent Rasmussen [72] Inventor: Donald W. Rasmussen, Downey, Calif.

Edoco Technical Products, Inc., Long Beach, Calif.

[22] Filed: June 30,1970

[21] Appl.No.: 51,219

[73] Assignee:

[52] US. Cl ..94/39, 94/51 [51] Int. Cl ..E0lc 19/00 [58] Field of Search ..94/39, 45, 51

[56] References Cited UNITED STATES PATENTS 3,194,130 7/1965 Guntert ..94/45 R 3,274,906 9/ 1966 Worson ..94/39 3,413,901 12/1968 Lusk ..94/39 3,401,610 9/ 1968 Hanson ..94/39 3,478,655 11/1969 Rasmussen ...94/39 3,495,509 2/1970 Lusk ..94/39 Mar. 14, 1972 Primary Examiner-Jacob L. Nackenoff Attorney-Fulwider, Patton, Rieber, Lee & Utecht 57] ABSTRACT A method and apparatus for inserting joint strip material in a slab of plastic concrete or the like. The apparatus includes an elongated frame for orientation transversely of the slab and transportable in successive movements longitudinally of the slab. The frame mounts a cart adapted to be driven along the frame and carrying a strip guide or tube movable through the plastic concrete to embed the joint strip material. The can also carries a pan which rides upon the concrete surface behind the strip guide to sense the height of the concrete, initiate operation of a means to adjust the height of the strip guide accordingly, and also smooth the concrete surface. This controls the depth of insertion of the strip material ans smooths the surface of the concrete disrupted by the insertion. The frame includes side forms engageable with the side edges of the concrete slab to preserve their integrity during the insertion operation, the forms being automatically retractable out of such engagement immediately upon longitudinal movement of the main frame. The joint strip material is unwound from a reel upon a strip unreeling traverse of the cart, held in position by clamping arms during an opposite insertion traverse of the cart, and severed upon completion of the insertion traverse. In a second embodiment feed wheels are used instead of the clamping arms.

24 Claims, 26 Drawing Figures Pam-mm! March 14, 1%?2 7 Sheets-She t 1 o NN\ 1 3 Mmmed Mmch 11% 7 Sheets-Sheet 2 INVENTOR.

arch ML, 51

Mmmtwd 7 Sheets-Sheet 4 INVENTOR.

Mmmd March Mr, 1%?2 7 Sheets-Sheet G INVENTOR. N/WLD ll Enama-muwm METHOD AND APPARATUS FOR HNSERTION 01F JOINT MATERIAL TN PLASTIC CONCRETE CROSS-REFERENCE The apparatus of the present invention is generally related to apparatus described in U.S. Pat. No. 3,274,906 entitled Joint Installation Apparatus," and issued Sept. 27, 1966. That apparatus is operative to insert joint strip material in plastic concrete, and particularly a cruciform shape strip material in canal linings and the like. Another related apparatus is that described in my U.S. Pat. No. 3,478,655 entitled Apparatus for Operation upon Elongated Section of Plastic Concrete or the Like," and issued Nov. 18, 1969. That apparatus utilizes a pair of wheels or disks adapted to roll through the plastic concrete while simultaneously embeddingjoint strip material.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a method and apparatus for inserting joint strip material in an expanse of plastic concrete, and more particularly to a method and ap paratus for inserting successive, longitudinally spaced apart lengths of strip material in an elongated plastic concrete slab to form spaced transverse joints.

2. Description of the Prior Art It is customary in the construction of comparatively large expanses of concrete to provide artificial joints along which thermal expansion and contraction of the concrete can occur. This avoids undesirable random cracking, which not only is unsightly but usually is productive of structural failure of the concrete slab.

Various methods and apparatus have been proposed in the prior art to provide such joints, the most successful being those which involve the embedment of an elongated strip of joint material in the plastic concrete. This provides a weakened plane joint in the uncured concrete, the concrete cracking along this weakened plane as it contracts during curing and hardening. One type ofjoint strip material is described in U.S. Pat. No. 3,023,681, issued Mar. 6, 1962, and entitled Combined Weakened Plane Joint Former and Waterstop."

The joint strip material of the referenced patent is generally cruciform in configuration, with the weakened plane joint being defined by the substantially vertically disposed portions of the cruciform shape. The horizontal portions of the cruciform configuration provide the desired water seal. Another form of joint strip material is described in U.S. Pat. No. 3,413,901, issued Dec. 3, 1968, and entitled Apparatus and Method for Inserting a Continuous and Solid Joint Strip into Plastic Concrete. The type of strip material mentioned in the latter patent is simply a ribbon or band of relatively thin plastic material which is vertically oriented in the concrete to provide a weakened plane, but without any integral means for water sealing.

The method and apparatus of the present invention is adapted to utilize either of the just described forms of joint strip material, as well as others ofthese general types.

Regardless of the form ofjoint strip material utilized, it must be installed rapidly and in proper orientation relative to the concrete since it must operate in conjunction with the paving equipment. The paving equipment normally operates at a comparatively high rate of speed and consequently utilizes a concrete "mix" which sets up or cures comparatively rapidly. Apparatus for inserting the longitudinal joint strip material, that is, the joints running longitudinally of the expanse of concrete, in the direction of travel of the paving equipment, is usually mounted upon the paving equipment itself and the strip material is simply unrolled from a storage reel and disposed within the plastic concrete during the forward progress ofthe paving equipment.

In contrast, the present invention is concerned with the problem of laying or embedding joint strip material transversely of an elongated slab of concrete, such as in the case ofa concrete highway. This type of operation poses special problems in that the paving equipment moves in a longitudinal direction, while the apparatus for inserting the transverse joint strip material moves generally transversely of the direction of movement of the paving equipment and consequently must effect embedment rapidly and efficiezntly so as not to slow the progress of the paving job. Attempts have been made in the prior art to combine the transverse: insertion apparatus with the paving equipment so as to avoid a start-stop" operation of the transverse insertion apparatus, but this results in considerable complexity and consequent lack of reliability.

A suitable apparatus for inserting joint strip material transversely must also be capable of inserting the joint strip material at a predetermined depth so that the controlled cracking provided by the embedded strip material is effective. Moreover, the disruption of the plastic concrete resulting from the insertion must be adequately smoothed over to remove ridges and surface imperfections which might other,- wise be present and felt by motorists using the concrete slab in the case of a highway. Proper vibration of the concrete about the inserted joint strip material is also important for structural reasons. In the prior art, the apparatus for inserting transverse joint strip material utilized means which were ineffective to accomplish these various functions in a simple and straightfon ward manner.

Another problem experienced in the use of apparatus of the prior art was a result of deliberate deformation of the strip material just prior to its insertion. More particularly, where the strip material is of the flat strip or band type, which ordinarily is relatively stiff and non-elastomeric in character, the strip material is relative incapable of being deformed in the plane within which it lies without encountering corrugating or wrinkling of an edge. One prior art apparatus has provided inserters which have corrugated portions to accommodate such wrinkling, but this introduces a requirement for close tolerances, presents a relatively high frictional drag on the strip material, and requires some means for forcibly thrusting or pushing the strip material into the inserter tube for subsequent deposition in the plastic concrete.

SUMMARY The present apparatus and method for inserting joint strip material transversely of an elongated slab of plastic concrete utilizes a frame which mounts a transversely movable car or cart. The cart is operated in conjunction with a pair of side forms which are also carried by the frame and which engage opposite edges of the concrete slab as the cart is moved transversely. A tape holding mechanism grasps the tape prior to an unreeling traverse of the cart, and a pan which trails the cart smooths the disrupted concrete, senses the level of the concrete, and initiates operation of elevation control mechanism associated with the cart to adjust the depth of insertion of the joint strip material by an inserter carrier by the cart. The inserter passes through an opening in the side form at the opposite edge of the concrete slab, at which point the tape is severed. The cart then returns in an unreeling traverse to its original position, followed by forward movement of the frame to repeat the operation. Initial forward movement of the frame is immediately followed by outward movement of the side forms.

The present apparatus is adapted to insert either the cruciform strip material previously mentioned, by utilizing a pair of disks or wheels which engage and urge the strip material into embedded position, or the flat band or strip type of material. The latter type of material can also be inserted by utilizing the pair of disks or wheels, or the band can be anchored or held momentarily at one side of the slab while the cart undergoes an insertion traverse. The clamping means, together with the frictional drag upon the strip, holds the strip in position during its insertion. There is relatively little stretching or subsequent creep of the strip material because the insertion tube in this arrangement is not characterized by any wrinkles or corrugations and consequently imposes relatively little friction upon the tape material as it leaves the insertion apparatus.

Preferably the concrete elevation sensing pan is arranged to trail the insertion tube or wheels so that it is capable not only of sensing the concrete surface height, but also is in position to simultaneously effect a smoothing action on the concrete which is disrupted during the insertion operation.

The provision of retractable side forms in the present apparatus preserves the structural integrity of the edges of the concrete slab during the insertion operation, and are automatically retractable upon forward movement of the main frame, being triggered or actuated by the initiation of this forward movement. This causes a sidewise movement of the forms on the edges of the concrete just prior to their outward, disengaging movement, thereby tending to prevent chunks or portions of the concrete from being pulled outwardly by virtue of the natural adhesion of the concrete to the side forms.

Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of joint insertion apparatus according to the present invention;

FIG. 2 is an enlarged side elevational view of the tube or guide inserter and the associated smoothing pan;

FIG. 3 is a top elevational view, on a reduced scale, of the apparatus of FIG. 1, particularly illustrating the angular arrangement of the sides of the apparatus relative to the front and rear members which thereby enables insertion of joint strip material diagonally;

FIG. 4 is an enlarged view taken along the line 4-4 of FIG. 3;

FIG. 5 is an enlarged detail view showing a portion of the tape holder, as generally indicated by the numeral 5 in FIG. 3;

FIG. 6 is an enlarged detailed view taken along the line 66 of FIG. 2;

FIG. 7 is an enlarged side elevational view of a portion of the piercing and severing mechanism for cutting any longitudinal strips of joint material through which the transverse strips ofjoint material must be disposed;

FIG. 8 is an enlarged view of the underside ofthe smoothing or sensing pan associated with the inserter of FIG. 2;

FIG. 9 is an enlarged view taken along the line 9-9 of FIG.

FIG. 10 is a partial perspective view, on an enlarged scale, illustrating the clamping mechanism for holding the joint strip material during an insertion traverse of the cart;

FIG. 11 is a detail top plan view of the locking lever for controlling movement of the tape holding or clamping mechanism relative to the main frame;

FIG. 12 is a diagrammatic and perspective view of various components which are operative to move the side forms inwardly and outwardly just subsequent to starting of longitudinal movement of the main frame;

FIG. 13 is an enlarged end elevational view of the system of FIG. 12, illustrating one of the side forms in its outward position;

FIG. 14 is a detail view illustrating one of the drive means for the supporting wheels of the main frame;

FIG. 15 is a side elevational view ofa portion of the tape inserter and holding mechanisms, illustrating the cart during an unreeling traverse;

FIG. 16 is a view similar to FIG. 15, but showing the tape holding mechanism in position holding the tape, and just prior to lowering of the tape insertion mechanism;

FIG. 17 is a view taken along the line 17-17 ofFIG. 16;

FIG. 18 is a view similar to FIG. 16, but illustrating the cart as it moves in an insertion traverse, opposite its direction of movement in FIG. 15;

FIG. 19 is a view similar to FIG. 18, but illustrating the completion of the insertion traverse, the cart being advanced beyond the side form and with the sensing head resting upon the concrete surface;

FIG. 20 is a transverse cross section through the concrete slab in the area of the inserted joint strip material;

FIG. 21 is a detail perspective view, on an enlarged scale, illustrating the structure generally indicated by the numeral 21 in FIG. 19;

FIG. 22 is a schematic view of certain hydraulic and electrical control mechanisms associated with the present apparatus;

FIG. 23 is a perspective view of a wheel inserter according to the present invention, as compared to the tube inserter of FIG. 2;

FIG. 24 is a side elevational view of the wheel inserter of FIG. 23;

FIG. 25 is a view taken along the line 25-25 of FIG. 24; and

FIG. 26 is a perspective view illustrating the drive system for the wheel inserter of FIG. 23.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and particularly to FIGS. 1 and 3 thereof, the present transverse joint strip material inserting apparatus comprises, generally, an elongated frame 10 adapted for transverse orientation across a concrete slab or the like. The frame 10 includes generally rectangular and vertically oriented front and rear subframes 100, each formed of an elongated channel 16 and an elongated member 22 overlying the channel 16 and connected thereto by suitable vertical diagonal post and truss elements, as illustrated. The frame 10 also includes a pair of generally rectangular, vertically oriented side frames 10b which are each formed of a pair of corner posts interconnected by a pair of cross members, as illustrated.

The frame 10 is adapted to be angularly oriented relative to the concrete slab within which joint strip material is to be embedded so that the joint strip can be disposed diagonally with respect to the concrete slab side edges. For this purpose, the subframes 10a are pivotally connected at their opposite ends to vertically spaced apart trunnions 13 which are integral with the corner posts 12 of the side frames 10b. This permits the angular orientation between the subframes 10a and 10b to be altered for the reason indicated, with the desired angular orientation maintained by diagonally oriented elements 15 secured at their ends to the channels 16, as best seen in FIG. 1. With this arrangement, the elements 15 can be adjusted in lengths, as by turnbuckles or the like (not shown), so that the inserting apparatus of the present invention can insert joint strip material at right angles to the edges of the concrete slab.

The corner posts 12 each rotatably mount a supporting wheel 14 adapted to travel along the sides of the concrete slab. At one extremity the channels 16 support a platform 18 which mounts a power source such as a motor generator 20. The motor generator 20 is associated with other equipment, which is omitted for brevity but which includes hydraulic pumps, control valves, actuating levers and the like.

The elements 22 and the channels 16 are characterized by disconnectable flanges 26 to permit the frame 10 to be separated in two pieces. Auxiliary channels and connecting elements can be disposed therebetween to increase the effective span of the frame 10, thereby accommodating the apparatus of different widths of highways, for example.

The frame 10 can be transported from one job site to another by any suitable towing means, utilizing a towing yoke 28. Only a portion of the yoke 28 is shown in FIG. 1. The vertical position of the relatively heavy yoke 28 is adjusted by an assembly which includes a hydraulic cylinder 30. During towing from one job site to another, the wheels 14 are removed from the posts 12 and the wheel axles 32 remounted in the posts 12 within fittings 34. This orients the wheels 14 at the right angles to their former locations.

A pair of elongated channels 36 run the length of the main frame and are pivotally mounted by suitable hangers and straps to the undersides of cross frame members 37 which extend between and are attached to the channels 116. With this arrangement the frame 110 can be angularly oriented, as previously indicated, without interference by the channels 36 or the structures supported by the channels 36.

The channels 36 extend beyond one end of the frame 10 and support a platform upon which is rotatably mounted a reel 38. The reel 38 is rotatable to unreel joint strip or tape 40 wound thereon.

As best seen in FIG. 20, the joint strip 40 used in this particular embodiment of the invention is relative thin and adapted to be oriented vertically in the plastic concrete to form the desired weakened plane joint. The joint strip 40 is relatively stiff and inelastic so that it is difficult to bend the material in its own plane without corrugating or wrinkling the edge. However, as will be described subsequently, the present apparatus is adapted to handle joint strip of this type by introducing it into the concrete at an angle to the concrete surface such that undesirable wrinkling or currugating of the joint strip is prevented.

As best seen in FIGS. 2 and 9, the channels 36 are rectangular in transverse cross section; and include downwardly opening slots for mounting a transversely movable cart 42. The cart 42 comprises a generally rectangular framework which includes a pair of elongated, spaced apart elements 44 oriented generally parallel to the main frame channels 16 and connected by a pair of cross members 4l6. Each corner of this rectangular structure mounts a pair of dual or tandem wheels 48 which are housed within the hollow interior of the associated channel 36 and roll along the opposite flanges defining the slot in the channel.

A pair of vertical elements 50, as partially seen in FIG. 2, are attached to the left end of the rectangular framework formed by the members 44 and 46, the lower ends of the elements 50 being reinforced by diagonal members 52 extending from the vertical elements 50 up to the right end of the cart 42.

The cart 42 pivotally supports an inserter frame 54 below it, the frame 54 being adapted to be raised or lowered relative to the cart 42. The inserter frame 54 is also generally rectangular, including a pair of elongated, spaced apart side members 56, as best viewed in FIGS. 2 and 9, which are connected together by a pair of cross members 58. The frame 54 further includes a pair of vertically oriented uprights 60 which are welded at their lower ends to the members 56 intermediate the ends ofsuch members 56.

A parallelogram arrangement is provided to pivotally support the inserter frame 54 from the cart 42. This takes the form of a pair of diagonally oriented, parallel arms 62 at each side of the inserter frame 54. The right ends of each pair of arms 62, as viewed in FIG. 2, are pivotally connected to the upper and lower ends of an upright 60 of the inserter frame 54, while the left ends of the arms 62 are pivotally connected to the upper and lower ends of a vertical element 50 of the cart 42.

Raising and lowering of the inserter frame 54 is accomplished by a hydraulic piston-cylinder 64 connected between the cross member 58 at the left end of the inserter frame 54 and cross member 46 at the left end of the cart 42. As will be seen, introduction of fluid under pressure into the cylinder 64 is operative to raise the inserter frame 54, the weight of the frame 54 being sufficient to lower it in the absence of such pressure. Of course, if desired, the cylinder 64 could be made double acting so that both raising and lowering of the inserter frame 54 would be pressure actuated.

An insertion mechanism 66 is secured to the underside of the inserter frame 54, as best seen in FIGS. 2, 6, and 9, and for this purpose includes a relatively wide channel 68 which is welded to the underside of the cross member 58 located at the left end of the inserter frame 54, as viewed in FIG. 2. With particular reference to FIG. 6, the underside ofthe channel 68 mounts a generally rectangular plate 70 by four nut and bolt assemblies 72 which include rubber elements 74 disposed between the channel 68 and the plate 70 for vibration isolation of the two parts. In this regard, the rear end of the plate 70 rigidly mounts an eccentric weight type vibrator 76 which is operative to vibrate the plate 70, which vibration is carried by a pair of diagonal plates 78 to an inserter guide or tube 80. The tube 80, as will be seen, is operative to discharge or extrude the joint strip 40 for embedment in the plastic concrete. The vibration imparted by the vibrator 76 is generally circular, being caused by an offset weight or the like rotating about a longitudinal centerline parallel to the tube 80. This causes a desirable consolidation of the concrete all around the embedded strip 40, as best illustrated in dash-dot outline in FIG. 20.

The tube 80 is a hollow, elongated] element having an interi' or passage which defines a cross section generally corresponding to the cross section of the joint strip material to be inserted, in this case a flat band or strip 40. The cross section is made large enough to permit the strip 40 to easily slide therethrough, and is absent any corrugations or other friction producing obstructions. The tube is straight and is characterized by a longitudinal axis which is inclined at an angle of approximately 3 to 15 degrees relative to the surface of the concrete in which the joint insert strip 40 is to be embedded. It has been found that at this angle the strip 40 can be introduced into the concrete, parallel to the surface thereof, and without any undesirable wrinkling ofthe strip 40. The tube 80 also includes a cutter mount 82 welded to its underside, the cutter mount 82 being provided as a support for a blade 83 having a plurality of carbide tipped cutter teeth. Approximately three teeth per inch of length has operated satisfactorily to cut longitudinally oriented sections of joint strip, as will be described in detail later.

As best seen in FIGS. 2 and 6, the forward or leading extremity of the tube 80 includes an opening 86 through which a rubber snubber 84 is disposed. The snubber 84 is biased against the joint strip 40 in the tube 80 by a compression spring 88 which is disposed about a bolt fastened at an angle to the tube 80. With this arrangement the joint strip 40 passing from left to right, as viewed in FIG. 2, is frictionally engaged by the snubber 84, but is permitted to slide past. However, the joint strip 40 cannot slide in the opposite direction because of the angular orientation of the snubber 84. The spring 88 and associated bolt are held at the proper angle for this by a right angle bracket 90 having a bent or offset portion 92, as best viewed in FIG. 6.

The trailing edge of the inserter tube 80 includes a generally rectangular cut out portion or opening 94 located between the upper and lower edges of the tube 80. As will be seen, this enables the joint strip 40 to be anchored or held as the cart 42 moves away in an unreeling traverse.

The rearward or trailing extremity of the inserter frame 54 also pivotally mounts a generally rectangularly shaped sensing or smoothing pan 96, the underside of which is generally configured as shown in FIG. 8. The sensing pan 96 crowds loose or available grout on the surface of the disrupted concrete into which the tape material 40 has been disposed, moves it into the disrupted channel, and smooths it down and about the inserted joint strip 40. The sensing pan 96 mounts an electric vibrator 98 on its upper side to consolidate the concrete about the inserted joint strip 40. For this purpose the vibrating action of the vibrator 98 is generally vertical to urge the grout downwardly.

The pan 96 includes a pair ofstrengthening elements or ribs 100 which extend longitudinally of the pan 96, and a pair of arms 102, only one of which is illustrated in FIG. 2, are pivotally connected to the ribs 100. The opposite ends of the transversely spaced arms 102 are pivotally connected to a pair of brackets 104 welded to the rear or trailing cross member 58 of the inserter frame 56, as best seen in FIG. 9. In addition, an upper arm 106, located approximately at the mid-portion of the pan 96 and between the arms 102, is pivotally connected winnat one end to a bracket 105 which is welded to the cross member 58 between the brackets 104. At its other end the arm 106 is pivotally connected to a central plate 108 welded to the pan 96 between the ribs 100.

The pan 96 is prevented from dropping beyond a certain point by a pair of tension springs 109 which are connected at their lower extremities to the ribs 100 and at their upper extremities to the rearward ends of a pair of tubular elements 112. The forward ends of the elements 112 are secured at their opposite extremities to the rear cross member 58 of the inserter frame 54, as best viewed in FIGS. 2, 9, and 16. Thus, although in operation the pan 96 rests upon the upper surface of the concrete, indicated generally by the numeral 114, the springs 109 support the pan 96 when the insertion mechanism 66 is raised. The pan 96 thus does not drop down upon the concrete 114 during an unreeling traverse of the cart 42. In addition, the tension of the springs 109 is adjustable so as to adjust the force with which the pan 96 presses against the plastic concrete. Such an adjustment allows for the weight of the particular pan and the flowability or plastic character of the concrete, for example. A pair of chains 110 are connected between the pan ribs 100 and the elements 112 and act as snubbers to prevent undue stretching of the springs 109, such as might occur ifa workman stepped on the pan 96.

The sensing function of the pan 96 will next be described. In this regard, a vertically oriented right angle bracket 116 is mounted to the pan plate 108 by a pair of bolts 118 which are disposed through a vertical slot provided in the bracket 116. The horizontally oriented or right angle upper portion of the bracket 116 is adjusted in height by loosening the bolts 118 and sliding the bracket 116 up or down. This right angle portion is engaged by a valve plunger 122 forming part of a hydraulic valve 124, as best viewed in FIG. 9. The valve 124 is secured to the rearward extremity of a plate 120 which is welded at its forward extremity to rearward cross member 58 of the inserter frame 54. As will be seen, operation of the valve 124 is effective to control the operation of the hydraulic cylinder 64 to raise and lower the inserter frame 54. With this arrangement, the height of the pan 96 relative to the concrete 114 determines the depth of insertion of the joint insert strip 40.

In operation of the apparatus illustrated in FIGS. 122, the operator operates suitable controls (not shown) by means of which the inserter tube 80 is raised above the concrete, and by means of which the drive means for the cart 42 causes the cart to move from left to right, as viewed in FIG. 1. This is termed an unreeling traverse because the joint strip 40 is unwound from the reel 38 during this traverse. More particularly, when the cart 42 begins to move in this traverse, the strip 40 is engaged by the snubber 84 so that the strip 40 is stopped from being pulled out of the tube 80 and is instead caused to move with the cart 42. Consequently, the strip 40 is unreeled from the reel 38 as the cart 42 moves on its wheels 48 within the channels 36 of the main frame during the unreeling traverse.

When the cart 42 is in the position illustrated in FIG. 16, the pan 96 will be located over the right side form 128 of a pair of side forms 126 and 128. When the operator lowers the inserter frame 54, the pan 96 will drop down and rest upon laterally oriented brackets 129 fastened to the side form 128. The brackets 129 support the pan 96 so that it does not fall down below the level of the concrete 114. The side forms 126 and 128, as will be seen, engage the, opposite sides of the concrete 114 and preserve its integrity during the joint strip insertion operation.

Whenever the inserter frame 54 moves toward the side form 128 it will engage a joint strip clamping mechanism 136, which will then move with the frame 54. More particularly, the side members 56 of the inserter frame 54 each includes an outwardly extending bracket 130 into which is threaded a stop bolt 132. The bolt 132 is adapted to engage a stop pad 134, as illustrated in FIG. 10, which is movable with the strip clamping mechanism, which is designated generally by the numeral 136. As will be seen, the engagement between the bolt 132 and the pad 134 causes the strip clamping mechanism 136 to travel to the right with the cart 42, as viewed in FIG. 15.

When the operator lowers the inserter frame 54 adjacent the side form 128, the strip clamping mechanism 136, as will be seen, is also caused to move downwardly with the frame 54 by virtue of engagement between the bolt 132 and a horizontal step portion of the pad 134, as best seen in FIG. 11. It is noted that in FIG. 11 the cart 42 will be moving to the left during this unreeling traverse.

The strip holding or clamping mechanism 136 is constructed generally in two halves, each of the halves being movable toward the other in order to effect a clamping action upon the end of the joint strip 40 through the opening 94 in the inserter tube 80. As best seen in FIG. 10, which is a view looking at the front of the present apparatus, the forward or leading half of the mechanism 136 includes a horizontally oriented element or operating arm 138 extending across the rear channel 36 and engaged at its rearward end by a bracket 140. The bracket 140 is pivotally connected to a rod 142 which extends up into a vacuum mechanism 144. Upon development of a vacuum in the mechanism 144, the rod 142 is urged upwardly to upwardly pivot the operating arm 138. The mechanism 144 is mounted upon a right angle bracket 146 which is secured to the opposite half of the mechanism 136, as will be seen.

The opposite or forward extremity of the operating arm 138 is welded to the extremities of three support arms 148 which extend forwardly over the forward channel 36 and then downwardly in front of the forward channel 36. At their lower, downturned ends the arms 148 are welded to an elongated sleeve 150 which extends along the forward side of the forward channel 16. The sleeve slidably accommodates a tube 152 whose opposite ends mount end fittings constituting stops 154. The stops 154 support the ends of the tube 152 and are secured by studs to the front face of the channel 36.

A vertically disposed rod 156 extends downwardly from the sleeve 150, being welded at its upper extremity to the sleeve 150. The rod 156 mounts a pair of vertically spaced stops 158 between which is vertically slidable a sleeve 162. The sleeve 162 and the opposite complemental sleeve 162 for the other half of the holding mechanism 136 are coupled by a pair of elements 164 and 166, one of which is loosely telescopable within the other (not shown) so that relative inward and outward movement of the sleeves 162 is permitted. The purpose of this will become apparent later.

Each sleeve 162 mounts a support structure 168 to which is secured the right angle bracket which constitutes the stop pad 134 previously described. Each support structure 168 also mounts a downwardly and inwardly extending holding or clamping element 170. The pair of elements 170 are in confronting relation and include offset end portions adapted to be disposed through the opening 94 in the insert tube 80, from opposite sides, for clamping the tape 40 therebetween.

The half of the tape holding mechanism 136 opposite that just described is located adjacent the rear main frame channel 16 and is constructed essentially the same. More particularly, the sleeve 162 thereof is vertically slidable upon a rod 172 which is welded to a horizontally oriented sleeve (not shown) identical to the sleeve 150. This latter sleeve is welded to the adjacent vertically oriented extremities of a pair of right angularly formed support arms 174 which are complemental to the support arms 148 already described in connection with the forward half of the mechanism 136. The forward or inner extremities of the arms 174 mount a vertically disposed coupler 176 which rests upon the upper surface of the adjacent arm 148. With this arrangement, the arms 174 are moved up and down by the coupler 176 whenever the arms 148 move up or down. Consequently, there is a corresponding, coordinated movement of the confronting ends of the clamping elements 170 toward and away from each other.

With the foregoing arrangement of the tape holding mechanism 136, movement of the cart 42 from left to right, as

lmm-i viewed in FIG. 1, effects engagement between the stop pads 134 and the stop bolts 132 on the cart 42. This causes the mechanism 136 to move to the right with the cart 42. As previously indicated, by virtue of the angle from which the structure is viewed in FIG. 10, this would in FIG. 10 appear as a movement to the left. Movement of the cart 42 to the right, as viewed in FIG. 1, is slowed by a deceleration mechanism which will be described subsequently. However, dealing now with the operation of the clamping mechanism 136, once the stop pads 134 and stop bolts 132 are engaged, and the cart is located adjacent the side form 128, the operator operates the controls which effect lowering of the inserter frame 54. As previously indicated, such controls are effective to relieve pressure in the cylinder 64 and allow the frame 54 to descend of its own weight. As the frame 54 moves downwardly, the bracket 130 mounted on the frame 54 engages a horizontal portion of the stop pad 134 which is carried by the tape holding mechanism 136. This brings the mechanism 136 down with the frame 54.

During this movement the sleeves 162 slide on the rods 156, and a weight 180 is caused to be raised. More particularly, and as best seen in FIG. 10, a pulley 182 is rotatably carried by a pulley bracket 184 welded to the sleeve 150. A complemental pulley 186 is rotatably mounted by a bracket 188 welded to the lower extremity of the sleeve 162, and a pulley 190 is rotatably supported by a bracket 192 secured to the channel 16 of the main frame 10. A line or cable 194 is secured to the bracket 184, extends downwardly and about the pulley 186, upwardly about the pulley 182, then about the pulley 190, about another pulley 196 which is rotatably mounted by a bracket 198 to the open upper end of a weight cylinder 200, and then is attached to the weight 180, which is vertically movable in the cylinder 200. The cylinder 200 is welded at its lower end to a cross member 202 which extends between and is welded to the pair of channels 16. A similar arrangement of pulleys and cables is provided for the other half of the clamping mechanism 136.

With this arrangement, as the mechanism 136 moves downwardly with the inserter frame 54, the weight 180 is raised. Then, when the cart 42 is moved to the left by the operator, as viewed in FIG. 1, the horizontal portions of the stop pads 134 are disengaged from the brackets 130, releasing the mechanism 136 for upward movement under the impetus of the weight 180. However, such upward movement does not occur until the vacuum is released from the vacuum mechanism 144 to thereby release the clamping action of the clamping arms 170 upon the joint strip 40. That is, with the tape holding mechanism 136 in its downward position, and a vacuum existing in the mechanism 144, the actuating arm 138 and the arms 174 are pulled upwardly to move the pair of clamping elements 170 toward each other to clamp the strip 40. In addition to this clamping action there is also a binding" between certain components of the mechanism 136 and the frame 10 which are normally slidable relative to one another. This binding prevents the mechanism 136 from moving to the left with the cart 42 during the unreeling traverse, and prevents the mechanism 136 from raising under the impetus of the weight 180. The way in which this binding action is developed will next be described.

When a vacuum exists in the mechanism 144, the clamping elements 170 are forcibly pressed toward one another. This causes sufficient deformation of the associated sleeves 162 and rods 156 that the sleeves 162 are not slidable vertically upon the rods 156. Instead, the sleeves 162 remain in their downward position as long as the vacuum exists in the vacuum mechanism 144. Consequently, even though the operator moves the cart 42 to the left, as viewed in FIG. 1, and the stop pads 134 and brackets 130 disengage, the binding action between the sleeves 162 and the rods 156 prevent the tape holding mechanism 136 from moving upwardly.

In addition, a locking action also occurs in that the tape holding mechanism 136 cannot move to the left with the cart 42 because the sleeves 0 and the horizontally disposed rods 152 are temporarily constrained against relative movement. More particularly, as best seen in FIGS. 10 and 11, and for both halves of the clamping mechanism 136, a locking link 204 is pivotally mounted intermediate its ends to the channel 36, and can be pulled at one end by an actuating cable 206 extending from the link 204 to a foot pedal or the like (not shown) actuable by the vehicle operator. By pressing the pedal the operator pivots the link 204 in a generally clockwise direction, as viewed in FIG. 11. The pivotal movement of the link 204 moves the free end of the link 204 into locking engagement with one of the teeth of a toothed rack 208 welded to an adjacent face of the sleeve 150. This prevents movement of the sleeve upon the associated tube or rod 152. Thus, when the operator wishes to maintain the mechanism 136 in position when the cart 42 is moved to the left, to thereby unreel the joint strip 40, he operates the cables 206 to lock the sleeves 150 upon the rods 152 on both clamping mechanism halves to thereby lock the mechanism 136 against the movement with the cart 42.

As the cart 42 proceeds to the left, a distance of perhaps five or six feet, the embedded joint strip 40 is frictionally engaged by the plastic concrete to such an extent that the clamping action of the mechanism 136 is no longer needed to hold the end of the tape 40 in position. At this point, the operator releases the vacuum in the vacuum mechanism 144 and also releases the tension upon the actuating cables 206. This allows the weight to move the mechanism 136 upwardly, and the bias of the weight 180 upon the pulleys 182 also pulls the mechanism 136 to the left, as viewed in FIG. 1, that is, in a direction away from the side form 128, until the sleeves 150 engage the inwardly located ones of the stops 154. This positions the mechanism 136 for re-engagement by the cart 42 when it returns on its unreeling traverse.

As best seen in FIGS. 2 and 7, as the cart 42 moves to the left on its insertion traverse, the joint strip 40 is embedded transversely of the concrete slab. Where the slab is of significant width, there usually exist one or more longitudinally oriented strips of joint strip material, such as indicated at 40A in FIG. 7. These strips are usually inserted during the paving operation and a passage must be cut through them in order to lay the transverse strip 40. Alternative structures can be used in the present apparatus to effect the cutting of such a strip 40A. As best seen in FIG. 7, one alternative is to provide the inserter frame 54 with a tape cutting assembly 210 mounted to the inserter frame 54. The assembly 210 includes a support arm 212 pivotally mounted to an upstanding plate 214 which is welded to the upper surface of the inserter frame plate 70. The arm 212 includes an upwardly extending extremity 216 which at its lower end provides the pivotal connection to the plate 70. The upper end of this portion is pivotally connected to the piston rod of a double acting hydraulic cylinder 218. The cylinder 218, in turn, is pivotally secured to a cross member 220 whose opposite extremities are welded to the opposite side members 56 of the inserter frame 54. Appropriate pressurization of the cylinder 218 by the operator pivots the arm 212 upwardly and downwardly, as will be apparent. A forward, downwardly extending extremity 222 of the arm 212 mounts a piercing element 224 which, when the arm 212 is down, is located in the position illustrated in dash-dot outline in FIG. 7. In this position the piercing element 224 will pierce and cut through the strip material 40A, providing a path through which the transverse strip 40 can be laid.

Referring now to FIGS. 3, 4, and 9, the means by which the cart 42 is driven back and forth along the length of the main frame 10 include an elongated chain 226 secured at its 0pposite ends to the opposite extremities of a chain plate 228. The plate is welded to a cross member 46 of the cart 42, while the chain 226 extends between and is trained about a pair of sprockets located at opposite ends of the main frame 10. One of the sprockets, which is illustrated at 230 in FIG. 3, is driven by a hydraulic motor 232 mounted to the frame 10 and under the control of the operator. During rotation of the sprockets 230, the upper run of the chain 226 is maintained in position on the chain plate 228 by a chain guard 234.

Provision is made for passage of the insertion tube 80 through the side form 126 as the cart 42 completes its insertion traverse. More particularly, the side form 126 includes an opening 236, as best viewed in FIG. 21, which is closed by flexible bristles 238. The bristles are held in position upon the form 126 by a holder 240 and are stiff enough to keep plastic concrete from flowing outwardly of the form 126. However, they are sufficiently flexible and resilient that the insertion tube 80 can pass through them.

Once the tube 80 has passed through the bristled opening 236, the joint strip 40 is severed just as the rear edge of the tube 80 is located inside of the form 126. Severance here, rather than outside the form 126, allows the side form 126 to move longitudinally without carrying the end of the strip 40 with it. Severance is accomplished by a cutter 242 carried at the lower end of a piston rod 244. The rod 244 is actuated downwardly by introducing fluid under pressure into a hydraulic cylinder 246 which is mounted to the inserter frame 54. Operation of the cylinder 246 is preferably under the control of the operator once the cart 42 has completed its insertion traverse. Once the joint strip 40 is severed by the cutter 242, the operator valves pressure into the opposite end of the cylinder 246 to raise the cutter 242 to the upper position illustrated in FIG. 18. The inserter frame 54 is then raised by the operator pressurizing the cylinder 64. This brings both the tube 80 and the pan 96 up and out of engagement with the concrete surface 114.

In its unreeling traverse toward the side form 128, as best viewed in FIGS. 3 and 5, the material 40 is unwound from the reel 38 and laid in a V-shaped channel 250 by a cylindrical guide 252. The guide 252 is held in position by virtue of being welded to a rod 254 which is mounted to a cross member 46 of the cart 42. This arrangement keeps the joint strip 40 from dropping down onto the concrete surface 114 and holds it in readiness to be pulled off the channel 250 and into the open leading end of the tube 80 for embedment in the plastic concrete during the insertion traverse of the cart 42, which would be to the lest as viewed in FIG. 1.

Generally while the cart 42 is moving through its unreeling traverse, the main frame is moved or indexed forwardly over a new section of the concrete slab to lay the next transverse strip. To permit such movement the side forms 126 and 128 must be pivoted outwardly out of engagement with the side edges of the concrete slab. It is an important feature of the present invention that the side forms 126 and 128 are maintained in position against the slab edges until the main frame 10 just begins to move forwardly. This provides a desirable wiping or shearing action so that outward movement of the forms does not cause portions of the slab side edges to be pulled out of the parent slab.

With particular reference to FIGS. 1, 12, and 13, each of the forms 126 and 128 is similarly suspended and operated and for brevity the following description is directed primarily to the form 128 and the mechanism associated with it. The opposite extremities of the form 128 are suspended from a pair of cables 256 and 258 which are trained, respectively, about a pair of pulleys 260 and 262 rotatably supported (not shown) upon the main frame 10. The cables further extend about a drum 264, which is rotatable by a handle 266 for adjusting the height of the form 128 to the height of the particular concrete slab 114.

The vertical orientation of the form 128 is established and maintained by an inwardly extending arm 268 attached at one end to the form 128 and connected at its other end to one of the main frame channels 16 by an upwardly extending chain 270. The chain 270 allows the form 128 to be pivoted inwardly and outwardly of the concrete slab 1 14, but establishes its vertical orientation against the slab 114.

The form 128 is pivoted or pulled away from the slab by means of a pair of cables 272 which are attached to the opposite extremities of the form 128. One run of each cable is trained about a pulley 274 which is rotatably mounted to an arm 276 fastened to the adjacent post 12 of the main frame 10. The cables 272 extend upwardly and toward each other,

and are then trained about a pair of pulleys 278 which are rotatably mounted to the forward main frame channel 16. Both the pulleys 274 and the pulleys 278 are located outwardly of the normal location of the side form 128 when it is in position against the side edge of the slab 114. The cables 272 pass from the pulleys 278 to the piston rod of a hydraulic cylinder 280 which is mounted to the rear main frame channel 16. Upon introduction of fluid under pressure into the cylinder 280, the cables 272 are moved inwardly, pulling the form 128 outwardly from the dash-dot position to the full line position illustrated in FIG. 13.

The outward movement of the form 128 raises a weight 282 whose bias is later utilized to return the form 128 to its position against the slab 114 once the pressure in the cylinder 280 is relieved. More particularly, a pair of cables 284 are connected, respectively, to the opposite extremities of the form 128 and extend inwardly and about a pair of pulleys 286 which are rotatably mounted to a pair of arms 288, respectively. The arms 288 are bolted to the lower ends of vertically oriented members 290 whose upper extremities are welded to the main frame channels 16. The cables 284 extend upwardly from the pulleys 286 and each is trained about one of a pair of pulleys 292. As best seen in FIG. 1, the pulleys 292 are rotatably mounted to the horizontally oriented main frame members 22, respectively. The cables 294 extend downwardly from the pulleys 292 to the weights 282. Consequently, outward movement of the form 128 by the hydraulic cylinder 280 raises the weights 282 and, when the pressure in the cylinder 280 is relieved, the weights 282 automatically move theform 128 back into engagement with the concrete slab 114.

As best seen in FIG. 14, each of the wheels 14 is individually driven by a hydraulic motor 294 which is mounted to the associated frame post 12. Each motor 294 drives a sprocket which is coupled by means of a drive chain 296 to a sprocket carried by the wheel 14, as will be apparent. The hydraulic motors are provided with pressurized fluid from a common source 308 by a pump 306, as best seen in FIG. 22. This is initiated by the operators actuation of a valve 310. Once actuated, the four hydraulic motors 294 exert equal traction on the four wheels 14 and thereby drive the apparatus along the length of the concrete slab 114.

Another sprocket is mounted to the output shaft of the hydraulic motor 294 and drives a chain 295 which is trained about a sprocket 297. The sprocket 297 is rotatably mounted to the lower cross member of the side frame 10b and integrally carries a smaller sprocket 299 which is connected by an interval chain 301 to a sprocket 303. The sprocket 303, in turn, is rotatably mounted to the frame 10b adjacent the sprocket 299. A number of indicators 305 are carried by the chain and are carried by the interval chain 301 past a marker 307 which is mounted to the side frame 10b. With this arrangement the operator of the present apparatus is provided with a means of determining how far to move the apparatus forwardly for the next transverse joint insertion. He merely watches until a particular indicator 305 comes into alignment with the marker 307, at which point he ceases to operate the hydraulic motors 294. The sprocket teeth ratios and sprocket sizes are of course suitably made to yield the interval readings desired, as will be apparent.

With reference to FIG. 22, the pressurized hydraulic fluid which operates the motors 294 also actuates a pressure switch 298 which initiates outward movement of the side forms 126 and 128. This means that just as the apparatus begins its movement longitudinally of the slab 114 the forms 126 and 128 will begin a wiping action in a longitudinal direction against the sides of the concrete slab 114. This slight movement or wiping action is immediately interrupted by tripping of the pressure switch 298, because the forms are then pivoted outwardly by the hydraulic cylinder 280. More particularly, actuation of the pressure switch 298 closes an electrical circuit which includes a holding relay 300. The relay 300, in turn, closes and maintains in closed position a switch 302. Thus, the initial pressure build up in the hydraulic motors 294 is effective to trip the mun-i switch 302, but the switch 302 stays closed even after the pressure drops off as the wheels 14 begin to rotate.

Once the switch 302 is closed, it energizes a solenoid actuated valve 304, admitting fluid under pressure to the hydraulic cylinder 280. As previously indicated, this is effective to move the side forms 126 and 128 outwardly.

FIG. 22 also illustrates the arrangement of the hydraulic valve 124 which is under the control of the valve plunger 122 carried by the inserter frame 54. The valve 124 adjusts the flow offluid under pressure from the pump 306 to the hydraulic cylinder 64, which raises and lowers the inserter frame 54. Thus, actuation of the plunger 122 by the sensing pan 96, as it rides up and down over the concrete surface 114 behind the inserter tube 80 is effective to raise and lower the inserter frame 54 and tube 80 accordingly. Moreover, location of the pan 96 behind the tube 80 enables the pan 96 to conveniently serve the function of smoothing any concrete disrupted by the pan 96.

FIG. 22 also illustrates the location of a solenoid actuated valve 312 which is controlled by the operator to apply hydraulic fluid to the cylinder 64 to manually raise the inserter frame 54, as when the cart 42 is being moved through an unreeling traverse. The valve 312 is operated by closure of an electrical switch 314 by the operator, as illustrated, to apply power from the power source 316 to a solenoid associated with the valve 312.

Referring now to FIG. 10, the present apparatus includes a deceleration mechanism for automatically slowing or decelerating the car 42 as it approaches the side form 128 during an unreeling traverse. Such mechanism is operative to adjust a usual and conventional speed control mechanism (not shown) which controls the speed of operation of the hydraulic motor 232 which drives the chain 226 pulling the cart 42.

The deceleration mechanism comprises, generally, an elongated arm 318 pivotally mounted to the forward one of the channels 36. The arm 318 is offset outwardly or forwardly of the channel 36 for engagement on its underside with a cam 320 mounted to the cart 42, as best seen in FIG. 9. As the cart 42 moves toward the side form 128, the cam 320 engages and moves the arm 318 upwardly to an increasing extent as the cart 42 continues its travel. Upward movement of the arm 318 is transmitted by an integral, upwardly extending arm extension 322 to a cord or cable 324 which extends to the speed control mechanism previously mentioned. The increasing pull of the extension 322 on the cable 324 effects an automatic slowing action on the cart 42 as it nears the side form 128, the closer the cart coming to the side form, the more it is slowed by the pull on the cable 324 and the action thereof on the speed control mechanism. This action causes the cart 42 to come to a standstill approximately in vertical alignment with the side form 128, at which point the operator manually operates the speed control mechanism to adjust the position of the cart 42 exactly in alignment, as will be seen.

Summarizing the operation of the present apparatus, and with particular reference to that embodiment which uses the inserter tube 80, the tape holding mechanism 136, and the tape cutting assembly 210, the cart 42 is first caused to move toward the side form 128 in an unreeling traverse by the operator's actuation of a lever which controls the speed mechanism (not shown). This controls the flow of hydraulic fluid to the hydraulic motor 232. As the cart 42 proceeds in its unreeling traverse, the operator also actuates the hydraulic drive motors 294 for the wheels 14. As previously mentioned, this also actuates the side forms 126 and 128 outwardlyjust as the main frame begins its longitudinal movement over the concrete slab 114 in position for insertion ofa transverse strip of the material 40.

The operator then manually stops the main frame 10 at the proper location by referring to the interval chain 301 of FIG. 14 for guidance. When the chain 301 and its associated indications shows that the frame 10 has reached the point where the next length of transverse joint strip is to be inserted, the operator stops further movement of the main frame 10 by cutting offthe flow of hydraulic fluid to the drive motors 294.

By this time the cart 42 will have been automatically decelerated by the action of the decelerating arm 318, and will also have engaged and picked up the holding mechanism 136. The mechanism 136 then moves with the cart 42 until both are located approximately in vertical alignment with the side form 128. The operator then makes whatever minute adjustments are necessary in the transverse location of the cart 42 by operating the cart drive motor 232.

Next, the operator actuates a valve which connects the en gine manifold to the vacuum mechanism 144 so that a vacuum is developed in such mechanism. This causes the clamping elements 170 to grip the joint strip 40 through the opening 94 in the inserter tube 80. The operator then admits fluid under pressure into the hydraulic cylinder 64, causing the inserter frame 54 to descend carrying the holding mechanism 136 and the clamped joint strip 40 down with it.

The just-described sequence of approach of the inserter frame 54 toward the side form 128, and clamping of the joint strip 40 prior to descent of the inserter frame 54 is illustrated in FIGS. 15 and 16.

At this time a wand or probe of a switch 178, as viewed in FIG. 3, is in engagement with an upright pole 249 which is mounted on the side form 128. This turns on the vibrators 76 and 98 for the inserter tube 80 and sensing pan 96, respectively, preparatory to movement of the cart 42 in its insertion traverse.

The operator then depresses a foot pedal (not shown) to lock the holding mechanism 136 in its lowered position, as best seen in FIG. 18, and next operates controls which admit fluid under pressure to the drive motor 232. At this same time the operator adjusts the speed control mechanism to thereby adjust the rate of travel of the cart 42 in its insertion traverse toward the side form 126.

As the cart 42 moves toward side form 126 in its insertion traverse, the joint strip 40 is pulled out of the inserter tube 80 by reason of the clamping of the end thereof by the clamping arms 170. Once the cart 42 has proceeded a short distance, in the order of approximately 10 feet, the operator releases the vacuum in the vacuum mechanism 144, so that the tape holding mechanism 136 automatically rises and re-indexes itself in position just to the left of the side form 128, as previously described.

Assuming that a length of longitudinal joint strip 40A exists in the concrete slab, and its location is fairly standard and therefore known, a cam 326 is located on the frame 10 coincident with the location of joint strip 40A. The cam 326 is secured to the forward one of the channels 36 along which the cart 42 rides, as best seen in FIG. 3, and is engaged by a wand or probe 328 carried by the cart. As the cart 42 reaches the point of engagement between the cam 326 and probe 328, the probe 328 is operative to actuate a valve carried by the cart 42, and this valve, through suitable and conventional hydraulic lines, causes fluid under pressure to be applied to the hydraulic cylinder-piston assembly 218, as seen in FIG. 7. This lowers the piercing element 224 and pierces the longitudinal joint strip 40A. The operation of the assembly 218 is of short duration so that the piercing element 224 immediately rises into the full line position shown in FIG. 7 once the piercing operation has been completed.

In the preferred embodiment of the present apparatus the piercing element 224 and its associated actuating mechanism is not used, the cutting of the longitudinal joint strip 40A being automatically accomplished by the sawtooth blade 83 attached to the underside of the inserter tube 80, as seen in FIG.

As the cart 42 approaches the side form 126, the operator manually slows the cart 42, and a wand or probe 248 associated with a switch and valve engages an upright pole 330 mounted to the side form 126. This is operative through suitable and conventional electrical and hydraulic lines to shut off the tube vibrator 76. Engagement of the probe 248 with the pole 330 is also effective to automatically operate the tape cutter by routing fluid under pressure to the cylinder 246. This drives the cutter 242 downwardly to sever the joint strip 40, as best seen in FIG. 19.

The cart 42 with the inserter frame 54 continues its travel toward the side form 126 until the pan 96 is almost off the slab of concrete 114. At this point, another wand or probe 332 carried by the cart 42, and associated with usual electrical and hydraulic equipment, is engaged by a cam 334 mounted to the forward channel 36 at the left end of the main frame 10, as seen in FIG. 3. This engagement is effective to stop operation of the pan vibrator 98. The operator then raises the inserter frame 54 by routing hydraulic fluid to the cylinder 64 just prior to the pan 96 dropping off the side form 126.

The cart 42 is then moved by the operator in an unreeling traverse, moving towards side form 128 to repeat the justdescribed cycle.

An alternative embodiment of the insertion mechanism is illustrated in FIGS. 23 through 26. In this embodiment, it is unnecessary to provide a tape holding mechanism 136 since the joint strip is positively pulled out of the insertion tube by a pair of rotating discs or wheels 336. An apparatus utilizing a similar pair of wheels 336 is described in detail in my US. Pat. No. 3,478,655, issued Nov. 18, 1969.

The pair of wheels 336 are rotatably carried upon a transversely oriented shaft 338 which is bent or deformed to define a pair of axes which are oppositely inclined relative to a horizontal axis, thereby orienting the inner surfaces of the wheels 336 in downwardly convergent relation to locate the lower peripheries thereof in closer proximity than the upper peripheries thereof. The proximity of the lower peripheries of the wheels 336 permits engagement, gripping, and release of the joint strip 40 during rotation of the wheels 336.

The opposite ends of the shaft 338 carrying the wheels 336 are rigidly secured to the confronting side members 56 of the inserter frame 54. On the outer side of each wheel 336 a drive chain 340 is trained about a sprocket 342 secured to the wheel. The other end of the chain 340 is trained about a sprocket 344 carried by a shaft 246 which is suitably rotatably mounted to the inserter frame 54. The opposite end of the shaft 346 carries another sprocket 344, which drives a chain 340 for rotation of the sprocket on the outside of the other wheel 336, as will be apparent.

A main sprocket 348 is mounted on the shaft 346 between the sprockets 344 and is coupled by a chain 350 to a sprocket 352 carried at one end of a shaft which is suitably rotatably mounted to the cart 42. The central portion of the shaft is split and is coupled by energization of the components of an electric clutch 354 mounted to the shaft parts. At the opposite extremity of the shaft is mounted a second sprocket 356 which is engaged by a chain 358.

The chain 358 extends upwardly and is trained about a sprocket 360 which is mounted on the same shaft as the central idler sprocket carried by the chain plate 228 which is illustrated in FIG. 4. With this arrangement, as the cart 42 is pulled back and forth by the chain 226, the sprocket-chain train forming the interconnection to the wheels 336 controls the rate at which the wheels 336 are positively driven. The clutch 354 is energizable by any suitable controls whereby the driving connection between the chain 226 and the wheels 336 is effected. I

As best seen in FIGS. 23, 24, and 25, the inserter tube 80a is cruciform in configuration to accommodate a cruciformshaped joint insert 40a. This type of insert is somewhat more resilient and stretchable, as compared to the strip or band type of joint insert 40 mentioned in connection with the embodiment of FIGS. 1 through 22. The showing of the cruciform joint strip 40a is included particularly to illustrate that the present apparatus is adapted to handle both relatively stiff or brittle insert materials, and also relatively resilient insert materials. The handling of either type is enabled by the positive pulling of the joint strip material out of the inserter tube, either by the tape holding mechanism 136 of the first embodiment,'or by the wheels 336 in the embodiment of FIGS. 23 through 26. The mechanism 136 can handle joint inserts like that of insert 40 or 40a, as can the wheels 336.

To facilitate engagement and gripping of the upwardly extending central portion of the cruciform joint insert 40a by the lower peripheries of the wheeTs 336, a rubber shield or apron 362 is fitted about the lower peripheries of the wheels 336 to define a space into which the lower peripheries depend. The apron 362 is secured about a complementally shaped opening 364 out in the upper rearward extremity of the inserter tube a, whereby access is had to the joint insert 40a within the tube 80a. The upper edge portion of the apron 362 is provided with a relatively heavy head so that it is suitably reinforced against bending during use. The upper portion of the aprafl 362 is also characterized by an upwardly and outwardly clllfie ing or divergent portion so that any plastic concrete moviti| upwardly upon the exterior surfaces of the apron 362- is caused to flow outwardly and drop back onto the concrete. surface 114.

The upper terminus of the apron 362 is made high enough that it is always located above the surface of the concrete. This prevents concrete from flowing downwardly into the area where the lower peripheries of the wheel 336 engage and posi-i tively pull against the joint insert 40a.

Operation of the embodiment of FIGS. 23 through 26 is es-;

sentially identical to the operation just described in conjunc"-i tion with the inserter tube 80. The main differences are that the engagement of the wand or probe 178 by the upright pole 249 on the side form 128 just prior to an insertion traverse not only turns on the tube and pan vibrators 76 and 98, but also energizes the electric clutch 354 to rotate the wheels 336. Similarly, when the cart 42 reaches the opposite form 126, engagement of the wand or probe 248 not only turns off the tube vibrator 76, but also de-energizes the electric clutch 354 to stop further rotation of the wheels 336.

Any disruption of the concrete existing immediately adjacent the forms 126 and 128 after the insertion operation is completed are touched up or finished by hand. This is attended to by concrete finishers who customarily touch up or finish rough places in the side edges of the concrete and elsewhere in the slab.

From the foregoing it will be apparent that the present apparatus is uniquely adapted to effect insertion of transverse joint strip material by utilizing either a strip holding mechanism or a pair of wheels to positively pull joint strip from an elongated, straight inserter guide or tube. This is in contrast to prior art systems which attempt to push the strip material through curved or scalloped inserter tubes. The straight tube of the present apparatus eliminates any necessity for bending or otherwise crimping the edges of the joint strip, being arranged at an angle of incidence of 4-l5 with respect to the surface of the concrete so that no undesirable bending is necessary in order to introduce the joint strip into the concrete. Also, it has been shown that the present apparatus provides a means for adjusting the depth of insertion of the joint strip by means of a pan which not only senses the height of the concrete but also follows the insertion equipment to provide a smoothing action as well.

The present apparatus also is unique in its provision of side forms which are automatically retracted just subsequent to longitudinal forward indexing of the main frame of the apparatus. Since it is only after slight initial longitudinal movement of the apparatus that the forms are retracted, there is an initial wiping action by the forms which tends to prevent chunks of the concrete side edges from being pulled out as the side forms pivot outwardly.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.

I claim:

1. Apparatus for insertion of elongated joint strip transversely of and within an elongated section of plastic concrete, said apparatus comprising:

an elongated main frame for orientation transversely of said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete;

a cart movable along said frame;

an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete; adjusting means operative to raise and lower said inserter frame;

inserter means carried by said inserter frame and adapted to receive said joint strip therein and further adapted for location of a portion thereof below the surface of said section of concrete for embedment of said joint strip in said concrete;

sensing means including a pan pivotably mounted to said inserter frame and adapted to ride upon the surface of said section of concrete in trailing relation to said inserter means;

control means including a portion responsive to the pivoted position of said pan for operating said adjusting means to raise and lower said inserter frame in correspondence with said pivoted position of said pan; and

strip pulling means for engaging said joint strip and positively pulling it out of said inserter means.

2. Apparatus according to claim 1 and including drive means on said frame to effect longitudinal movement of said frame over successive transverse portions of said concrete, said drive means including indicating means movable in correspondence with movement of said frame, and further including indicia on said frame cooperative with said indicating means to display the extent of said movement of said frame.

3. Apparatus according to claim 1 wherein said frame comprises longitudinally spaced apart front and rear subframes and a pair of end frames pivotally mounted to said subframes, respectively, whereby said subframes may be oriented diagonally of the longitudinal side edges of said elongated section of plastic concrete while said end frames remain oriented for travel parallel to said side edges.

4. Apparatus according to claim 1 wherein said portion of said control means is carried by said inserter frame.

5. Apparatus according to claim 1 wherein said inserter means includes an elongated joint strip guide having a substantially straight longitudinal axis lying at an angle ofapproximately 4 to relative to the surface of said section of concrete.

6. Apparatus according to claim 1 and including chain drive means coupled between said cart and said frame for moving said cart along said frame.

7. Apparatus according to claim 6 wherein said inserter means includes a pair of wheels whose lower peripheries are located and arranged in convergent relation for gripping said joint insert.

8. Apparatus according to claim 7 wherein said wheels are detachably coupled to said chain drive means for rotation of said wheels during movement of said cart along said frame.

9. Apparatus according to claim 6 wherein said inserter means includes an elongated joint strip tube through which said joint strip is movable, said tube having an opening through which said lower peripheries of said wheels project for engagement with said joint strip.

10. Apparatus according to claim 9 wherein said inserter means further includes a protective apron surrounding said opening and extending upwardly for termination above the surface of said section of concrete whereby said plastic concrete is dammed away from said opening and the lower peripheries of said wheels.

11. Apparatus according to claim 10 wherein the upper portion of said apron is curved upwardly and outwardly of said wheels whereby any plastic concrete flowing upwardly upon said apron is constrained to thereafter fall downwardly upon the surface ofsaid section of concrete.

12. Apparatus according to claim 1 wherein said pan is configured to crowd together and smooth down concrete disrupted by said inserter means.

13. Apparatus according to claim 1 wherein said strip pulling means comprises a clamping mechanism movably mounted to said main frame for travel along a portion of the length thereof, said clamping mechanism including a pair of confronting clamping arms operative for movement toward one another and under said pan to clamp said joint strip therebetween.

14. Apparatus for insertion of elongated joint strip transveb sely of and within an elongated section of plastic concrete said apparatus comprising:

an elongated main frame for orientation transversely of said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete;

a cart movable along said frame;

an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete;

adjusting means operative to raise and lower said inserter frame;

inserter means carried by said inserter frame and including an inserter tube adapted to receive said joint strip therein and further adapted for location of a portion of said inserter tube below the surface of said section of concrete for embedment of said joint strip in said concrete, said inserter tube being characterized by a trailing end having an opening provided therein between the upper and lower termini of said inserter tube; and

strip pulling means for engaging said joint strip and including a clamping mechanism movably mounted to said main frame for travel along a portion of the length thereof, said clamping mechanism including a pair of confronting clamping arms operative for movement toward one another and into opposite sides of said opening in said inserter tube to grip said joint strip therethrough.

15. Apparatus according to claim 14 and including a pan carried by said inserter frame in trailing relation to said inserter means for riding upon and smoothing plastic concrete disrupted by said inserter means, and wherein said clamping arms are sufficiently elongated and downwardly and inwardly oriented that said pan is enabled to pass over the confronting extremities of said arms.

16. Apparatus according to claim 14 and including a cutter means carried by said inserter frame and including a cutter aligned with the end of said inserter tube and operative to shear against said end and move across said opening in said inserter tube to sever said joint strip from said inserter tube.

17. Apparatus according to claim 16 and including a pair of side forms pivotally carried by said main frame for engagement with the opposite side edges of said section of concrete, and further including means for operating said cutter as said end of said inserter tube is aligned with the inner surface of one of said side forms whereby said joint strip may be severed inwardly of said one of said side forms.

18. Apparatus according to claim 14 and including a reel on said main frame for storing a quantity of said joint strip, and further including locking means operative to constrain said clamping mechanism against movement relative to said main frame whereby said joint strip may be engaged by said clamping arms during an insertion traverse of said cart toward said reel whereby said joint insert is pulled out of said inserter tube for embedment in said concrete.

19. Apparatus according to claim 18 wherein said cart and said clamping mechanism include means operative upon engagement of said clamping mechanism by said cart, upon travel of said cart in an unreeling traverse away from said reel, to couple said clamping mechanism to said cart for travel therewith in said unreeling traverse.

20. Apparatus according to claim 19 and including snubbing means carried by said insertion means and operative to prevent relative movement between said joint strip and said insertion tube upon travel of said cart in said unreeling traverse whereby said joint strip is paid out from said reel.

21. Apparatus according to claim 14 and including a pair of side forms pivotally carried by said main frame for engagement with the opposite side edges of said section of concrete,

and further including drive means operative to effect longitudinal movement of said main frame, and control means interconnected between said side forms and said drive means for outwardly pivoting said side forms away from said section of concrete only subsequent initiation of said longitudinal movement of said main frame whereby said side forms are adapted to longitudinally wipe against the side edges of said section of concrete prior to disengaging said side edges.

22. Apparatus for inser'tion of elongated joint strip transversely of and within an elongated section of plastic concrete, said apparatus comprising:

an elongated main frame for orientation transversely of said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete;

a cart movable along said frame;

an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete;

adjusting means operative to raise and lower said inserter frame; 1

inserter means carried by said inserter frame and including an inserter guide adapted to receive said joint strip therein and further adapted for location of a portion of said inserter guide below the surface of said section of concrete for embedment of said joint strip in said concrete, said inserter means further including a pair of wheels whose lower peripheries are located and arranged in convergent relation for gripping said joint insert and positively pulling said joint strip out of said inserter guide; and

a pair of side forms pivotally carried by said main frame for engagement with the opposite side edges of said section of concrete, and further including drive means operative to effective longitudinal movement of said main frame, and control means interconnected between said side forms and said drive means for outwardly pivoting said side forms away from said section of concrete only subsequent initiation of said longitudinal movement of said main frame whereby said side forms are adapted to longitudinally wipe against the side edges of said section of concrete prior to disengaging said side edges.

23. Apparatus for insertion of elongated joint strip transversely of and within an elongated section of plastic concrete, said apparatus comprising:

an elongated main frame for orientation transversely of said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete;

a cart movable along said frame;

an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete;

adjusting means operative to raise and lower said inserter frame;

inserter means carried by said inserter frame and adapted to receive said joint strip therein and further adapted for location of a portion thereof below the surface of said section of concrete for embedment of said joint strip in said concrete;

sensing means including a pan pivotally mounted to said inserter frame and adapted to ride upon the surface of said section of concrete in trailing relation to said inserter means;

control means including a portion responsive to the pivoted position of said pan for operating said adjusting means to raise and lower said inserter frame in correspondence with said pivoted position of said pan;

strip pulling means for engaging said joint strip and positively pulling it out of said inserter means; and

a pair of said forms pivotally carried by said main frame for engagement with the opposite side edges of said section of concrete, at least one of said side forms including support means extending outwardly thereof for support of said sensing pan upon movement of said pan outwardly of said one of said side forms.

24. Apparatus according to claim 23 and including drive means for moving said cart along said frame; speed control means operative to vary the speed at which said drive means moves said cart; and means on said cart and on one extremity of said main frame and adapted for movement in correspondence with movement of said cart relative to said main frame to thereby operate said speed control means to automatically decelerate said cart as said cart approaches said one extremity of said main frame. 

1. Apparatus for insertion of elongated joint strip transversely of and within an elongated section of plastic concrete, said apparatus comprising: an elongated main frame for orientation transversely of said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete; a cart movable along said frame; an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete; adjusting means operative to raise and lower said inserter frame; inserter means carried by said inserter frame and adapted to receive said joint strip therein and further adapted for location of a portion thereof below the surface of said section of concrete for embedment of said joint strip in said concrete; sensing means including a pan pivotably mounted to said inserter frame and adapted to ride upon the surface of said section of concrete in trailing relation to said inserter means; control means including a portion responsive to the pivoted position of said pan for operating said adjusting means to raise and lower said inserter frame in correspondence with said pivoted position of said pan; and strip pulling means for engaging said joint strip and positively pulling it out of said inserter means.
 2. Apparatus according to claim 1 and including drive means on said frame to effect longitudinal movement of said frame over successive transverse portions of said concrete, said drive means including indicating means movable in correspondence with movement of said frame, and further including indicia on said frame cooperative with said indicating means to display the extent of said movement of said frame.
 3. Apparatus according to claim 1 wherein said frame comprises longitudinally spaced apart front and rear subframes and a pair of end frames pivotally mounted to said subframes, respectively, whereby said subframes may be oriented diagonally of the longitudinal side edges of said elongated section of plastic concrete while said end frames remain oriented for travel parallel to said side edges.
 4. Apparatus according to claim 1 wherein said portion of said control means is carried by said inserter frame.
 5. Apparatus according to claim 1 wherein said inserter means includes an elongated joint strip guide having a substantially straight longitudinal axis lying at an angle of approximately 4* to 15* relative to the surface of said section of concrete.
 6. Apparatus according to claim 1 and including chain drive means coupled between said cart and said frame for moving said cart along said frame.
 7. Apparatus according to claim 6 Wherein said inserter means includes a pair of wheels whose lower peripheries are located and arranged in convergent relation for gripping said joint insert.
 8. Apparatus according to claim 7 wherein said wheels are detachably coupled to said chain drive means for rotation of said wheels during movement of said cart along said frame.
 9. Apparatus according to claim 6 wherein said inserter means includes an elongated joint strip tube through which said joint strip is movable, said tube having an opening through which said lower peripheries of said wheels project for engagement with said joint strip.
 10. Apparatus according to claim 9 wherein said inserter means further includes a protective apron surrounding said opening and extending upwardly for termination above the surface of said section of concrete whereby said plastic concrete is dammed away from said opening and the lower peripheries of said wheels.
 11. Apparatus according to claim 10 wherein the upper portion of said apron is curved upwardly and outwardly of said wheels whereby any plastic concrete flowing upwardly upon said apron is constrained to thereafter fall downwardly upon the surface of said section of concrete.
 12. Apparatus according to claim 1 wherein said pan is configured to crowd together and smooth down concrete disrupted by said inserter means.
 13. Apparatus according to claim 1 wherein said strip pulling means comprises a clamping mechanism movably mounted to said main frame for travel along a portion of the length thereof, said clamping mechanism including a pair of confronting clamping arms operative for movement toward one another and under said pan to clamp said joint strip therebetween.
 14. Apparatus for insertion of elongated joint strip transversely of and within an elongated section of plastic concrete, said apparatus comprising: an elongated main frame for orientation transversely of said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete; a cart movable along said frame; an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete; adjusting means operative to raise and lower said inserter frame; inserter means carried by said inserter frame and including an inserter tube adapted to receive said joint strip therein and further adapted for location of a portion of said inserter tube below the surface of said section of concrete for embedment of said joint strip in said concrete, said inserter tube being characterized by a trailing end having an opening provided therein between the upper and lower termini of said inserter tube; and strip pulling means for engaging said joint strip and including a clamping mechanism movably mounted to said main frame for travel along a portion of the length thereof, said clamping mechanism including a pair of confronting clamping arms operative for movement toward one another and into opposite sides of said opening in said inserter tube to grip said joint strip therethrough.
 15. Apparatus according to claim 14 and including a pan carried by said inserter frame in trailing relation to said inserter means for riding upon and smoothing plastic concrete disrupted by said inserter means, and wherein said clamping arms are sufficiently elongated and downwardly and inwardly oriented that said pan is enabled to pass over the confronting extremities of said arms.
 16. Apparatus according to claim 14 and including a cutter means carried by said inserter frame and including a cutter aligned with the end of said inserter tube and operative to shear against said end and move across said opening in said inserter tube to sever said joint strip from said inserter tube.
 17. Apparatus according to claim 16 and including a pair of side forms pivotally carried by said main frame for engagement witH the opposite side edges of said section of concrete, and further including means for operating said cutter as said end of said inserter tube is aligned with the inner surface of one of said side forms whereby said joint strip may be severed inwardly of said one of said side forms.
 18. Apparatus according to claim 14 and including a reel on said main frame for storing a quantity of said joint strip, and further including locking means operative to constrain said clamping mechanism against movement relative to said main frame whereby said joint strip may be engaged by said clamping arms during an insertion traverse of said cart toward said reel whereby said joint insert is pulled out of said inserter tube for embedment in said concrete.
 19. Apparatus according to claim 18 wherein said cart and said clamping mechanism include means operative upon engagement of said clamping mechanism by said cart, upon travel of said cart in an unreeling traverse away from said reel, to couple said clamping mechanism to said cart for travel therewith in said unreeling traverse.
 20. Apparatus according to claim 19 and including snubbing means carried by said insertion means and operative to prevent relative movement between said joint strip and said insertion tube upon travel of said cart in said unreeling traverse whereby said joint strip is paid out from said reel.
 21. Apparatus according to claim 14 and including a pair of side forms pivotally carried by said main frame for engagement with the opposite side edges of said section of concrete, and further including drive means operative to effect longitudinal movement of said main frame, and control means interconnected between said side forms and said drive means for outwardly pivoting said side forms away from said section of concrete only subsequent initiation of said longitudinal movement of said main frame whereby said side forms are adapted to longitudinally wipe against the side edges of said section of concrete prior to disengaging said side edges.
 22. Apparatus for insertion of elongated joint strip transversely of and within an elongated section of plastic concrete, said apparatus comprising: an elongated main frame for orientation transversely of said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete; a cart movable along said frame; an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete; adjusting means operative to raise and lower said inserter frame; inserter means carried by said inserter frame and including an inserter guide adapted to receive said joint strip therein and further adapted for location of a portion of said inserter guide below the surface of said section of concrete for embedment of said joint strip in said concrete, said inserter means further including a pair of wheels whose lower peripheries are located and arranged in convergent relation for gripping said joint insert and positively pulling said joint strip out of said inserter guide; and a pair of side forms pivotally carried by said main frame for engagement with the opposite side edges of said section of concrete, and further including drive means operative to effective longitudinal movement of said main frame, and control means interconnected between said side forms and said drive means for outwardly pivoting said side forms away from said section of concrete only subsequent initiation of said longitudinal movement of said main frame whereby said side forms are adapted to longitudinally wipe against the side edges of said section of concrete prior to disengaging said side edges.
 23. Apparatus for insertion of elongated joint strip transversely of and within an elongated section of plastic concrete, said apparatus comprising: an elongated main frame for orientation transversely oF said elongated section in overlying relation thereto and including means at its opposite extremities enabling longitudinal movement of said frame over successive transverse portions of said concrete; a cart movable along said frame; an inserter frame carried by said cart and pivotable downwardly of said cart for location adjacent the surface of said section of concrete; adjusting means operative to raise and lower said inserter frame; inserter means carried by said inserter frame and adapted to receive said joint strip therein and further adapted for location of a portion thereof below the surface of said section of concrete for embedment of said joint strip in said concrete; sensing means including a pan pivotally mounted to said inserter frame and adapted to ride upon the surface of said section of concrete in trailing relation to said inserter means; control means including a portion responsive to the pivoted position of said pan for operating said adjusting means to raise and lower said inserter frame in correspondence with said pivoted position of said pan; strip pulling means for engaging said joint strip and positively pulling it out of said inserter means; and a pair of said forms pivotally carried by said main frame for engagement with the opposite side edges of said section of concrete, at least one of said side forms including support means extending outwardly thereof for support of said sensing pan upon movement of said pan outwardly of said one of said side forms.
 24. Apparatus according to claim 23 and including drive means for moving said cart along said frame; speed control means operative to vary the speed at which said drive means moves said cart; and means on said cart and on one extremity of said main frame and adapted for movement in correspondence with movement of said cart relative to said main frame to thereby operate said speed control means to automatically decelerate said cart as said cart approaches said one extremity of said main frame. 